One method for producing such a part is for example described in document EP-1 927 453 to produce a tailgate lining for an automotive vehicle. The method described in this document provides for over-molding a metallic core with a plastic material in order to produce the reinforced tailgate lining.
In this method, the metal core is kept at the center of a mold cavity by holding means and a plastic material is injected into the mold cavity so as to coat the metal core, which makes it possible to obtain a reinforced structural part having a satisfactory stiffness.